Rare butterflies and bees will find refuge in the countryside on the Dorset – Hampshire border after two new butterfly banks were created on the Martin Down Farmer Cluster. The chalk banks, on farmland close to the Martin Down National Nature Reserve, have been planted with kidney vetch and seven species of native wildflowers. The rare Small Blue Butterfly lays its eggs, lives and feeds exclusively on kidney vetch.
The Martin Down Farmer Cluster is a group of 15 farmers who farm the area around the nationally important Martin Down National Nature Reserve. Since 2017 they have worked together to support the wildlife which makes their home on the reserve and surrounding farmland by improving and developing wildlife-friendly habitat alongside productive agriculture.
The new butterfly banks were created on a farm within the Cranborne Estate, which is part of the Martin Down Farmer Cluster. The project was funded by Natural England as part of a wider project of species enhancement through their ‘Creating Spaces for Species’ project and managed on their behalf by the Dorset-based Footprint Ecology. The chalk banks for small blue butterfly were part of a range of projects including scraping away the soil and sowing juniper seeds on Martin Down National Nature Reserve
Megan Lock, Farmland Biodiversity Advisor with the Game & Wildlife Conservation Trust (GWCT), is the Farmer Cluster Facilitator. She provides conservation advice and support to the farmer cluster and helped facilitate the project. Megan said:
“After the banks were constructed, we planted nearly 400 kidney vetch plug plants, as well as seeding the banks with Horseshoe and Tufted Vetches, Common Bird’s-foot-trefoil, Self-heal, Lady’s Bedstraw, Devil’s-bit Scabious and Salad Burnet.
“These plants should thrive in the nutrient-poor soil but still leave lots of bare earth for mining bees and burrowing wasps. The Small Blue Butterfly has been chosen by the cluster farmers as one of their priority species. This new habitat should help them increase their range around the Martin Down NNR. The new butterfly banks will also be included in our monitoring programme so we will be able to measure the impact of this conservation work.”
The Small Blue Butterfly is known for being the smallest butterfly found in the UK, although it is not particularly blue in colour. The chalk downland of the Martin Down National Nature Reserve is a key stronghold for this threatened species.
The banks are approximately 30m long and 1-2m high but are situated on slopes so look much larger with a south-facing flank. They were constructed by digging a trench and burying the topsoil from the bank and adjacent scrape. The chalk sub-soil is then mounded on top covering the topsoil. This created bank and scrape features that are approximately 600-900 sq m in size.
The Martin Down Farmer Cluster is one of around 200 similar groups of farmers working together for wildlife in the UK. The Martin Down farmers have chosen turtle dove, hedgehogs, harvest mice, arable flora, bumblebees, small blue butterfly, dark-green fritillary, Duke of Burgundy and lapwing, soil organic matter and chalk downland as the priorities for their conservation work.
Since forming the farmer cluster in 2017, the Martin Down farmers achievements have included planting more than 10km of new hedgerows and increasing pollinator habitat by 50%, installing barn owl boxes, creating 21 turtle dove puddles and ponds and five new butterfly banks, creating habitat for grey partridge and monitoring hedgehogs. As facilitator Megan carries out wildlife monitoring to measure the impact of their work.
The new butterfly banks were created with the help of the staff of Cranborne Estate and Footprint Ecology.